Machining Strategy Determination for Single- and Multi-Material Wire and Arc Additive Manufactured Thin-Walled Parts

Area of Science:

• Materials Science and Engineering
• Manufacturing Technology

Background:

• Wire and Arc Additive Manufacturing (WAAM) offers high production capacity but results in surface irregularities, necessitating secondary machining.
• Surface waviness and unstable cutting forces complicate machining strategy selection for WAAM parts.

Purpose of the Study:

• To determine the optimal machining strategy for WAAM components by evaluating specific cutting energy and local machined volume.
• To assess the machinability of creep-resistant steel, stainless steel, and their combination produced via WAAM.

Main Methods:

• Comparative analysis of up-milling and down-milling strategies.
• Calculation of removed volume and specific cutting energy for different materials and deposition types.
• Assessment of surface roughness and machinability under varying conditions.

Main Results:

• Machined volume and specific cutting energy are key factors influencing WAAM part machinability, overriding traditional depth-of-cut parameters.
• Up-milling achieved a surface roughness of 0.1 µm, though results showed instability.
• Material hardness did not significantly impact as-built surface processing, and no machinability difference was observed between single- and multi-material components at low machined volumes.

Conclusions:

• Up-milling is a promising strategy for improving the surface finish of WAAM parts, yielding a 0.1 µm roughness.
• Specific cutting energy and machined volume are critical parameters for predicting WAAM machinability.
• Hardness is not a primary factor for selecting machining strategies on WAAM components.